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OSU Extension

College of Food, Agricultural, and Environmental Sciences

CFAES
August 3, 2021 - 8:00am -- lehman.488@osu.edu

Fall and winter grazing seems a long way off as we take a peek at the forecast of warm and sunny weather. However, now is the time to start thinking about planting cool season annuals and winter cover crops to feed livestock in the cold months. Optimal planting time for these crops is in August to allow them to maximize yield before putting cattle or sheep on them in September or October.

Grazing is the most economical way to feed livestock, especially when grain prices are high. The wide array of forage varieties, such as cool season grasses, legumes, brassicas, and small grains, for fall grazing allows you to customize your seed mixes to give a complete feed to your animals. This grazing method is a great way to utilize fields that laid fallow for the summer or fields that were in wheat or another small grain. Seeding technique will vary on the type of field you are planting. If you are seeding into any type of crop stubble, drilling will be best. On the other hand, you can overseed into suppressed pasture or hay fields to allow the seeds to germinate. Regardless of seeding, always make sure to run a soil test for pH and nutrients prior to planting. It can prevent a lot of headaches after the fact.

As I mentioned, there is quite a variety of forages you can plant for fall grazing purposes. At Ohio State, a pasture-based lamb trial examined the differences among grazing lambs on stockpiled fescue, oats (100 lb seed/acre), or turnips (3 lb seed/acre). This particular experiment no-till drilled seed into glyphosate-terminated pastures in the middle of August 2019. The forages were allowed to establish for approximately 90 days before lambs were turned out to graze from mid-November to the end of December.

What is most interesting about this experiment is the nutrient content of the forages provided. The stockpiled pasture averaged about 16% crude protein over the course of the grazing period. Oats started off strong at 22% crude protein but dwindled to 14% by the end of the trial. On the other hand, turnips started out average at 15% crude protein and finished strong at about 21% protein. Even at the end of December, when many animals are offered hay or grain, the lambs on turnip pasture were receiving 21% crude protein feed.

Another benefit of turnips is their low neutral detergent fiber (NDF) content. Neutral detergent fiber is an indicator of feed intake due to gut fill. Therefore, when turnips average 18% NDF and oats and stockpiled pasture average about 55%, the lambs will be able to eat that much more feed to continue putting on the pounds. Dry matter yield for the forages was greatest during the start of the trial with about 3,100 to 3,200 pounds of dry matter per acre for each of the forages. Oats did not hold up because of a killing frost and offered about 450 pounds of dry matter per acre at the end of December, whereas turnips and stockpiled pasture still offered about 1,000 pounds per acre.

While that is a single instance in research, there are other options and they each have specific rates of application for mixes. They include red clover (2 to 4 lb/acre), hairy vetch (25 lb/acre), or winter peas (50 lb/acre) in the legume family; kale (3.5 to 4 lb/acre), rape (2 to 4 lb/acre), swede (1.5 to 2 lb/acre), and radishes (1 to 2 lb/acre) in the brassica group; wheat, rye, or triticale in the small grains family (all 6 to 12 lb/acre); or annual ryegrass (6 to 10 lb/acre) for a cool season annual grass.

Do keep in mind that some forages, such as small grains and turnips, have been known to accumulate nitrates after drought and can be a risk for nitrate poisoning. On another note, brassicas are also a risk for bloat, atypical pneumonia, haemolytic anemia, or polioencephalomalacia. Pennsylvania State University recommends a slow adjustment to a brassica pasture and that brassicas should not constitute greater than 75% of the animal’s diet.

In summary, prepare for late summer forage planting as you would other times of year – soil test, prepare fields, and seed properly – and select varieties to create a nutritionally comprehensive mix. Do your research to find out which varieties and mixes are best for your operation because every farm is unique in their needs. Lastly, be mindful of forage varieties and their possible ill-effects if not managed correctly.

 

Haley Zynda is an OSU Extension ANR Educator and may be reached at 330-264-8722.

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